Concrete Boat Cements Its Way To High Speeds

November 11, 2022 by Ryan Flowers 12 Comments

Steel is scarce. Wood is not an option. And you need a boat now. These wartime circumstances drove innovation in all kinds of crazy directions, and one somewhat less crazy direction — concrete boats. As [Peter Sripol] demonstrates in the video below the break, making an RC concrete boat isn’t hard. Making a fast one on the other hand is. But that didn’t stop him from trying, and we think the effort deserves a look.

Starting with a basic displacement style hull, [Peter] and his cohorts experimented with a simple RC boat that worked, but could only move at slow speeds. They turned things up a notch or two and instead modeled their concrete boat after an RC speedboat hull that they had on hand.

The construction methods left a lot to be desired though, and they even tried various wire meshes as rebar, but they proved too heavy. Eventually though, they got a working hull, and had some fun with it. Rather than try to make the hull watertight with a rudder and propeller, they opted for a ducted fan and an airboat style rudder to make what they call the “world’s fastest concrete boat”.

Whether it’s the fastest or not is unconfirmed, but it is fast and actually gets on step fairly nicely. We applaud the exploration of alternative materials and the experimentation with different build methods. If building things with concrete floats your boat, then be sure to check out this concrete pinhole camera.

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A multi-colored chair with a stainless steel frame sits on wooden legs against a grey background.

Recycled Chairs Bring The Subway To Your Living Room

November 6, 2022 by Navarre Bartz 38 Comments

Public transit seats have a rough life. Enduring a number of wear cycles that would make your sofa weep, they take a beating and have to keep looking presentable. When trains and buses are retired, where do the old seats go? A team from the MIT Hobby Shop investigated what was happening to the seats from retiring MBTA Red Line cars and recycled them into stylish chairs.

After some sleuthing and many emails, the MBTA relinquished a number of old subway seats to the team. Since the subway seats didn’t have legs, wood from old church pews was used to create bases. It took one pew end support to create each set of legs, which were cut out on a bandsaw. The old dark stain was sanded off, and the bases were finished with three coats of gel topcoat, letting the natural beauty of the old oak shine through.

We love seeing old things given new life here at Hackaday. If you want to see some more recycled furniture, check out this tire table, this upcycled jeans chair, or these best practices for making box forts.

A man and a woman stand at opposite ends of a wooden-framed bicycle. It has 20" tires and a long, black seat. A rack extends over the front tire for carrying small items.

Plywood Bicycle Makes Frame Building More Accessible

November 4, 2022 by Navarre Bartz 37 Comments

Bike frames are simple on the surface, but can quickly become complicated if you want to fabricate one yourself. Brazing and welding tend to be less common skills than knowing how to bolt things together, so [Arquimaña] has brought us the OpenBike to make the process accessible to more people.

An open-source set of files designed for CNCs and 3D printers, the OpenBike uses readily available materials like sheet plywood to make a sturdy, if unconventional-looking, bicycle. Like many other consumer goods, most bike frames are currently built in Asia. This allows for economies of scale, but removes locals from the design process. By using simpler tools, OpenBike allows for more local direction of what features might be needed for a particular region.

Shifting even a small portion of trips to more active forms of transport is an important part of lowering carbon emissions, so making bikes a more attractive means of transportation is always welcome. What might be important in one region might be superfluous and expensive in another (multiple gears in a hilly region, for example). OpenBike could be especially useful as a way to rapid-prototype different feature sets for a particular region before committing to a more traditional frame-building technique for larger batches of bikes.

If you want to see some other bike hacks, why not check out this extending bicycle, this steampunk recumbent trike, or these bike hacks from around the world?

via Yanko Design

Lighting Up Glue Stick Bicycle Tyres With RGB

October 31, 2022 by Danie Conradie 28 Comments

Being visible to motorists is a constant concern for cyclists, but we doubt [The Q] will have this problem with his RGB LED illuminated tires made from glue sticks.

The project started with a set of 3D-printed tire molds that bolt to the standard wheels. A bot of melted glue sticks is poured into the mold, allowed to cool, and the mold sections are removed with the help of a heat gun after cooling. We doubt the weight and hardness make the tires particularly practical, but you can’t make normal tires glow from the inside.

The idea to illuminate the tires probably came after molding, because they had to be cut off to fit the LEDs. [The Q] built a simple hot wire jig with a piece of nichrome wire between two screws and used it to cut a few millimeters from the inside of the tire and fit a sleeved RGB LED strip in the wheel. Power come from a set of three 18650 batteries housed with a wireless controller in a 3D printed hub-mounted enclosure.

Like [The Q]’s hubless and partial wheel bicycles, it’s a definite head-turner, with function following form.

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Flight Simulator Focuses On The Other Side Of The Cockpit Door

October 25, 2022 by Dan Maloney 22 Comments

When one thinks of getting into a flight simulator, one assumes that it’ll be from the pilot’s point of view. But this alternative flight simulator takes a different tack, by letting you live out your air travel fantasies from the passenger’s point of view.

Those of you looking for a full-motion simulation of the passenger cabin experience will be disappointed, as [Alex Shakespeare] — we assume no relation — has built a minimal airliner cabin for this simulator. That makes sense, though; ideally, an airline pilot aims to provide passengers with as dull a ride as possible. Where a flight is at its most exciting, and what [Alex] captures nicely here, is the final approach to your destination, when the airport and its surrounding environs finally come into view after a long time staring at clouds. This is done by mounting an LCD monitor outside the window of a reasonable facsimile of an airliner cabin, complete with a row of seats. A control panel that originally lived in an airliner cockpit serves to select video of approaches to airports in various exotic destinations, like Las Vegas. The video is played by a Pi Zero, while an ESP32 takes care of controlling the lights, fans, and attendant call buttons in the quite realistic-looking overhead panel. Extra points for the button that plays the Ryanair arrival jingle.

[Alex]’s simulator is impressively complete, if somewhat puzzling in conception. We don’t judge, though, and it looks like it might be fun for visitors, especially when the drinks cart comes by.

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DIY Bike Wheels Welded With Rebar

October 24, 2022 by Lewin Day 43 Comments

[Liebregts] is working on a trike design, and needed a pair of wheels to go up front. Regular bicycle wheels wouldn’t do, as they’re not designed to work with a single-sided support. They also wanted to be able to mount disc brakes. Thus, they set about building a set of custom wheels to do the job.

The build began with a regular set of 20″ bike wheel rims with all the spokes taken out. A ring of steel rebar welded on the inner perimeter gave the rims more strength. A set of hubs and axles were then fabbed up with a welder and lathe, with provisions for bolting on disc brake components. Lengths of rebar were then welded in as non-adjustable spokes. Next, it was time for a coat of paint. Finally [Liebregts] mounted the tires and brakes, and called the job done.

Obviously, it is possible to buy wheels specifically for trike builds. However, [Liebregts] found it difficult to find exactly what they wanted, particularly where the disc brake option was concerned. The best option was a custom build. The resulting wheels are obviously much heavier than traditional bike wheels, but they’re also likely a fair bit stronger, too. If you need to weigh down a tarpaulin, for example, these wheels might just do the trick.

We’ve seen some other crazy wheels on trikes before, too! Oh, and who says wheels need to be a full circle, anyway? Creativity will never cease to amaze!

Velomobile Gets Electric Assist

October 22, 2022 by Bryan Cockfield 37 Comments

What do you get when you throw all accepted bicycle designs out the window and start fresh? Well, it might look a bit like [Saukki’s] velomobile.

Most bikes come in a fairly standard, instantly-recognizable shape which has been popular for over a century now. While it’s a vast improvement over its predecessor, the penny-farthing bicycle, there’s no reason that a bike needs to have this two-triangle frame shape other than that a pretentious bicycle racing standards group says they have to. If you want to throw their completely arbitrary rulebook out of the window, though, you can build much more efficient, faster bikes like recumbents or even full-fairing velomobiles. And if you want to go even faster than that, you can always add a standard ebike motor kit to one.

This is a lot harder than putting a motor on a normal bicycle. Bicycles tend to have standardized parts and sizes, and [Saukki]’s velomobile is far from the standard bike. First, he needed custom mounts for the display and also for the battery, which he needed to make extra wide so its weight wouldn’t rip through the carbon fiber body. The emergency brake lever motor cutoff needed to be dismantled to work with his control system too, and finally the mid-drive motor needed a custom mount as well. It’s a TSDZ2 motor that comes with torque-sensing pedal assist.

The changes didn’t stop there. The velomobile max speed is much higher than a standard bike. This called for some gear ratio changes, in the form of a monster 60-tooth chain ring.

This leads to the one major problem with this build which is that the velomobile can achieve such high speeds on its own that the electric assist cuts out for most of the ride. There is a legal requirement over much of Europe that e-bikes only have pedal assist (without a throttle) and that they stop assisting above a specific speed. But if you want to build an e-bike that pushes the boundary of the law instead of strictly adhering to it, take a look at this one which uses a motor from a washing machine.

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